#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <assert.h>


char* my_strcat(char* dest, const char* src)
{
	char* tmp = dest;
	assert(dest && src);
	while (*dest != '\0')
		dest++;
	while (*dest++ = *src++)
		;
	return tmp;
}


int main()
{
	char arr1[20] = "abc";
	char arr2[] = "def";
	my_strcat(arr1, arr2);
	printf("%s\n", arr1);
	return 0;
}
